Production system and process of PK catalyst

Abstract

A PK catalyst production system comprises a palladium acetate feeding tank, a ligand feeding tank, an organic acid feeding tank and a catalyst reaction kettle, and the palladium acetate feeding tank, the ligand feeding tank, the organic acid feeding tank and the catalyst reaction kettle are each provided with a heat exchange interlayer and a stirring device. A feeding hole of the palladium acetate feeding tank is connected with a palladium acetate source and an N-methyl pyrrolidone source, a feeding hole of the ligand feeding tank is connected with a 4, 6-dihydroxy-2-methylpyrimidine source and an N-methyl pyrrolidone source, a feeding hole of the organic acid feeding tank is connected with a maleic acid source and an N-methyl pyrrolidone source, and a feeding hole of the organic acid feeding tank is connected with a reaction kettle. The palladium acetate feeding tank, the ligand feeding tank and the organic acid feeding tank are respectively used for feeding materials to the catalyst reaction kettle. The device is simple in structure and low in maintenance cost, and can be used for efficiently synthesizing the PK catalyst.

Description

Technical Field

[0001] The invention relates to the field of chemical industry, and in particular to a production system and process of a PK catalyst. Background Art

[0002] PK is polyketone resin, a hard and dense material with a smooth, white and shiny surface. It has a high elastic modulus, high rigidity and hardness, and its specific strength and specific rigidity are close to those of metals. It also has a low friction coefficient, is wear-resistant, and has good dimensional stability. Polyketone resin can partially replace copper, zinc, aluminum, steel and other metals and is widely used in automobiles, machinery manufacturing, precision instruments, office appliances, military and other industries. Polyketone resin has the characteristics of high hardness and wear resistance, so it is widely used in the manufacture of various gears, rollers, bearings, conveyor belts, springs, cams, bolts, and various pump bodies, housings, impeller friction bearings and other mechanical equipment structural parts.

[0003] PK is a linear crystalline high molecular polymer obtained by alternating copolymerization of carbon monoxide, ethylene and propylene. During the copolymerization process, a catalyst needs to be added. Since the production cost of the catalyst is high and it is easy to lose, designing a low-cost catalyst to enhance the competitiveness of PK products is an urgent problem to be solved by technicians in this field. Summary of the invention

[0004] One of the purposes of the present invention is to provide a production system of PK catalyst in view of the deficiencies of the prior art, which has a simple structure and low maintenance cost and can be used for efficiently synthesizing PK catalyst.

[0005] The second object of the present invention is to provide a process for synthesizing PK catalyst using the above production system, which has mild reaction conditions, high single-pass conversion rate, and few side reactions, which can significantly reduce production costs and enhance the market competitiveness of PK products.

[0006] The technical solution for achieving one of the purposes of the present invention is: a PK catalyst production system, comprising a palladium acetate feeding tank, a ligand feeding tank, an organic acid feeding tank, and a catalyst reactor, wherein the palladium acetate feeding tank, the ligand feeding tank, the organic acid feeding tank, and the catalyst reactor are all provided with a heat exchange interlayer and a stirring device, the feed port of the palladium acetate feeding tank is connected to a palladium acetate source and an N-methylpyrrolidone source, the feed port of the ligand feeding tank is connected to a 4,6-dihydroxy-2-methylpyrimidine source and an N-methylpyrrolidone source, the feed port of the organic acid feeding tank is connected to a maleic acid source and an N-methylpyrrolidone source, and the palladium acetate feeding tank, the ligand feeding tank, and the organic acid feeding tank respectively feed the catalyst reactor.

[0007] The palladium acetate feeding tank, the ligand feeding tank, the organic acid feeding tank and the catalyst reactor are all filled with inert gas.

[0008] It also includes a catalyst intermediate tank, through which the catalyst reactor provides PK catalyst to the polymerization process, and the catalyst intermediate tank is filled with inert gas.

[0009] The technical solution for achieving the second object of the present invention is: a process for synthesizing a PK catalyst using any of the above-mentioned production systems comprises the following steps:

[0010] 1) Pass 80-90°C hot water into the heating interlayer of the palladium acetate feeding tank, the ligand feeding tank, the organic acid feeding tank, and the catalyst reactor and keep it warm;

[0011] 2) respectively adding N-methylpyrrolidone into the palladium acetate feeding tank, the ligand feeding tank, and the organic acid feeding tank, and stirring;

[0012] 3) Add palladium acetate to the palladium acetate feeding tank, control the mass ratio of palladium acetate to N-methylpyrrolidone to 1:4000, until it is completely dissolved; add 4,6-dihydroxy-2-methylpyrimidine to the ligand feeding tank, control the mass ratio of 4,6-dihydroxy-2-methylpyrimidine to N-methylpyrrolidone to 1:888.9, until it is completely dissolved; add maleic acid to the organic acid feeding tank, control the mass ratio of maleic acid to N-methylpyrrolidone to 1:158.7, until it is completely dissolved;

[0013] 4) Control the palladium acetate feeding tank and the ligand feeding tank to feed the catalyst reactor at the same time, and stir the reaction at normal pressure for 3 hours;

[0014] 5) Control the organic acid feeding tank to feed the catalyst reactor, stir and react for 2 hours under normal pressure to obtain a mixture containing PK catalyst.

[0015] Step 2) The mass ratio of N-methylpyrrolidone in the palladium acetate feed tank, the ligand feed tank, and the organic acid feed tank is 6:4:5.

[0016] In step 3), palladium acetate is solid particles, 4,6-dihydroxy-2-methylpyrimidine is solid particles, maleic acid is solid particles, the molar ratio of palladium acetate to 4,6-dihydroxy-2-methylpyrimidine is 1:1.5-3, and the molar ratio of palladium acetate to maleic acid is 1:3-21.

[0017] Step 5) The mixture containing the PK catalyst is sent to a PK polymerization process, and the solvent used in the PK polymerization process is N-methylpyrrolidone.

[0018] The invention also provides a PK catalyst prepared by any of the above processes.

[0019] The present invention also provides use of the PK catalyst in catalyzing a PK polymerization process.

[0020] Furthermore, the PK polymerization process uses ethylene, carbon monoxide, and propylene as polymerization monomers, and the amount of PK catalyst added is 1500 kg.

[0021] The above technical solution has the following beneficial effects:

[0022] 1. The production system of the PK catalyst of the present invention is provided with a palladium acetate feeding tank, a ligand feeding tank, an organic acid feeding tank, a heat exchange interlayer, and a stirring device, which are used to prepare a corresponding raw material solution system, ensure that the raw materials for synthesizing the PK catalyst are uniformly mixed in the form of a solution, ensure the synthesis effect, and facilitate the control of the molar ratio of each raw material, thereby improving the utilization rate of the raw materials.

[0023] 2. The production process of the PK catalyst of the present invention uses palladium acetate, a transition metal of the eighth group, as the main catalyst to initiate polymerization, the bidentate ligand 4,6-dihydroxy-2-methylpyrimidine as the ligand, maleic acid as an anion co-catalyst, and N-methylpyrrolidone (NMP) as the catalyst solvent to form an anion organic metal complex, which can reduce the use of the expensive catalyst palladium acetate and reduce the production cost of PK. Its mechanism is as follows:

[0024] Pd(C2H3O2)2+C5H6N2O2→Pd(C2H3O2)2-C5H6N2O2

[0025] Pd(C2H3O2)2C5H6N2O2+C4H4O4→Pd(C2H3O2)2C4H4O4-C 31 H 33 O4P2-

[0026] C4H4O4;

[0027] The palladium acetate / 4,6-dihydroxy-2-methylpyrimidine / maleic acid catalytic system has high catalytic activity for ethylene and carbon monoxide polyketones. These ligands show higher catalytic activity than 1,3-bis[bis(2-methoxyphenyl)phosphino]propane in the process of polyketone synthesis. The synthesis route is simple, the yield is high, the cost is low, the ligand structure is novel, the catalytic activity is high, and it has a simpler structure and a lower molecular weight. The development of new bidentate ligands in the polymerization catalytic system plays an important role in improving the catalytic activity of polyketone polymerization.

[0028] When Pd 2+ When the ion oxidation state is high, the olefin complexes with it, and electron donation is dominant; the greater the electron cloud density of the olefin double bond, the easier it is to donate electrons to the metal, thus forming a stable bond. Free olefins are usually susceptible to attack by electrophilic reagents, and when olefins are combined with Pd 2+When complexed, alkenes are susceptible to attack by nucleophiles. When bonding with alkenes, the feedback bond is dominant; the stronger the electron-withdrawing property of the substituent on the olefin, the easier it is to accept the metal d electrons to feedback to the antibonding orbital of the olefin. At this time, the CC double bond distance of the olefin is significantly longer than when the giving bond is dominant. The way coordination bonds are formed: the metal and the ligand are both half-filled orbitals; the metal is an empty orbital, while the ligand is a full orbital or vice versa, and the metal and the ligand each provide an empty orbital and a full orbital.

[0029] Palladium acetate is used as the main catalyst. It is relatively stable to air and moisture, and is easily soluble in organic solvents. It is easy to disperse evenly in the polymerization solvent to ensure the catalytic effect. Palladium acetate is easy to form a σ bond with the ligand to obtain the corresponding Pd-C bond σ-complex, thereby realizing a series of functional group conversions. In the polymerization process, palladium acetate, as a precursor of the catalyst, is transformed into a metal organic complex in the catalytic reaction under the coordination of the ligand. The palladium complex is used as a homogeneous catalyst for the polymerization reaction of polyketone resin. The palladium acetate complex coordinates with the ethylene and propylene bonds, thereby activating the ethylene and propylene CH bonds to form a complex, which is easily attacked by nucleophilic CO, accepts CO to obtain a carbonyl compound and then replaces the olefin, thereby initiating the polymerization of the polyketone resin. Using 4,6-dihydroxy-2-methylpyrimidine as a ligand, the nitrogen ligand 4,6-dihydroxy-2-methylpyrimidine (C5H6N2O2) is introduced into the ligand structure to reduce the steric hindrance effect of the ligand, provide lone pair electrons to the active center ion of palladium acetate through the -N axial coordination of the ligand electrons, and form a stable complex with the main catalyst center metal palladium ion. The 4,6-dihydroxy-2-methylpyrimidine ligand produces a polymer with higher molecular weight and more stability at a high temperature of 80°C, effectively improving the physicochemical properties of the polyketone resin. The 4,6-dihydroxy-2-methylpyrimidine ligand exhibits higher catalytic activity than 1,3-bis[bis(2-methoxyphenyl)phosphino]propane in the process of polyketone synthesis, achieving a simple synthetic route, high yield, low cost, novel ligand structure, high catalytic activity, simpler structure and lower molecular weight. By introducing maleic acid containing acidic groups into the catalyst system to form ionic bonds, the reaction speed increases when the acidic group ratio increases, but too high an acidic group ratio affects polymer addition and is not conducive to molecular weight growth. Depending on the product grade and polymerization operation requirements, the molar ratio of maleic acid: palladium acetate varies between 3:1 and 21:1.

[0030] In addition, the production process of the present invention utilizes N-methyl pyrrolidone (NMP) as a catalyst solvent. In the acetone solvent with a smaller polarity, 70% of palladium acetate is found to be a monomer, while in N-methyl pyrrolidone (NMP), this ratio increases to 100%, that is to say, the solid particles of palladium acetate are completely dissolved. The solubility of palladium acetate in N-methyl pyrrolidone (NMP) forms a homogeneous catalyst system. Since the polymerization solvent adopted by the present invention also adopts N-methyl pyrrolidone (NMP), the catalyst solvent is the same as the polymerization solvent adopted by the present invention, therefore, the catalyst solvent and the polymerization solvent can be recycled and reused, avoiding the undesirable reaction caused by the catalyst solvent being different from the polymerization solvent.

[0031] 3. In the production process of the PK catalyst of the present invention, the theoretical molar ratio of palladium to ligand is 1:1. Insufficient ligand will lead to the plating of metal palladium, and excessive ligand will reduce the activity of the catalyst. The present invention sets the excess to 3 times to compensate for the formation of some inert, soluble Pd compounds and impurities in the ligand.

[0032] Further description is given below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a connection schematic diagram of the production system of the present invention.

[0034] In the attached drawings, 1 is a palladium acetate feeding tank, 2 is a ligand feeding tank, 3 is an organic acid feeding tank, 4 is a catalyst reactor, and 5 is a catalyst intermediate tank. DETAILED DESCRIPTION

[0035] In the present invention, the standards of palladium acetate, 4,6-dihydroxy-2-methylpyrimidine, maleic acid (maleic acid), and N-methylpyrrolidone used in the catalyst preparation are as follows:

[0036] Catalyst Raw Material Purity Table

[0037]

[0038] Example 1

[0039] See also Figure 1The production system of PK catalyst includes a palladium acetate feeding tank 1, a ligand feeding tank 2, an organic acid feeding tank 3, and a catalyst reactor 4. The palladium acetate feeding tank 1, the ligand feeding tank 2, the organic acid feeding tank 3, and the catalyst reactor 4 are all provided with a heat exchange interlayer and a stirring device, and are all filled with inert gas. The feed port of the palladium acetate feed tank 1 is connected to the palladium acetate source and the N-methylpyrrolidone source, the feed port of the ligand feed tank 2 is connected to the 4,6-dihydroxy-2-methylpyrimidine source and the N-methylpyrrolidone source, and the feed port of the organic acid feed tank 3 is connected to the maleic acid source and the N-methylpyrrolidone source. The palladium acetate feed tank 1, the ligand feed tank 2, and the organic acid feed tank 3 respectively feed the catalyst reactor 4. Further, it also includes a catalyst intermediate tank 5. The catalyst reactor 4 provides PK catalyst to the polymerization process through the catalyst intermediate tank 5. The catalyst intermediate tank 5 is filled with inert gas. Obviously, a catalyst intermediate pump is provided between the catalyst reactor and the catalyst intermediate tank, and a catalyst feed pump is provided at the discharge port of the catalyst intermediate tank. The specifications of the relevant equipment are shown in the following table:

[0040] Equipment tag Device Name Specifications (50,000 tons / year PK) quantity Material 1 Palladium acetate feeding tank <![CDATA[V=0.7m 3 ]]> 1 S30408 2 Ligand feed tank <![CDATA[V=0.7m 3 ]]> 1 S30408 3 Organic acid feed tank <![CDATA[V=0.7m 3 ]]> 1 S30408 4 Catalyst reactor <![CDATA[V=3.0m 3 ]]> 1 S30408 Catalyst intermediate pump Q=2.0t / h P=0.2MPa(G) 2 combination 5 Catalyst intermediate tank <![CDATA[V=3.0m 3 ]]> 1 S30408 Catalyst feed pump Q=1.0t / h P=4.0MPa(G) 2 combination

[0041] Example 2

[0042] The PK catalyst was synthesized intermittently using the production system of Example 1:

[0043] 1) The palladium acetate feed tank 1, the ligand feed tank 2, the organic acid feed tank 3, the catalyst reactor 4, and the catalyst intermediate tank 5 are all heated and kept warm by a 90°C hot water jacket.

[0044] 2) First, add the catalyst solvent N-methylpyrrolidone to the palladium acetate feed tank 1, the ligand feed tank 2, and the organic acid feed tank 3, stir and heat to 80° C. The catalyst solvent addition amount control value of the palladium acetate feed tank 1 is 600 kg, the catalyst solvent addition amount control value of the ligand feed tank 2 is 400 kg, the catalyst solvent addition amount control value of the organic acid feed tank 3 is 500 kg, and the total catalyst solvent addition amount is 1500 kg.

[0045] 3) 150 g of solid palladium acetate particles were weighed and poured into palladium acetate feeding tank 1, and dissolved in the tank for 2 hours.

[0046] 4) 450 g of ligand 4,6-dihydroxy-2-methylpyrimidine (DHP) solid particles were weighed and poured into the ligand feed tank 2, where they were dissolved for 3 hours.

[0047] 5) 3.15 kg of organic acid maleic acid (MA) solid particles were weighed and poured into the organic acid feeding tank 3, and dissolved in the tank for 3 hours.

[0048] 6) Then the palladium acetate dissolved in the palladium acetate feed tank 1 and the ligand 4,6-dihydroxy-2-methylpyrimidine (DHP) dissolved in the ligand feed tank 2 are simultaneously placed in the catalyst reactor 4 and allowed to react for 3 hours. The reaction temperature is controlled at 80° C. and the pressure is normal pressure.

[0049] 7) After palladium acetate and the ligand react for 3 hours, the maleic acid dissolved in the organic acid feed tank 3 is injected into the catalyst reactor 4. The reaction time is 2 hours, and the reaction temperature is controlled at 80°C and the pressure is normal pressure.

[0050] 8) The catalyst palladium complex generated in the catalyst reactor 4 has a total reaction time of 5 hours, which meets the 24-hour consumption of 50,000 tons / year and 3 shifts. It is sent to the catalyst intermediate tank 5 through the catalyst intermediate pump, and then metered into the polymerization process through the catalyst feed pump.

[0051] The catalyst formula changes with the change of the molar ratio of the main catalyst palladium acetate and the co-catalyst organic acid maleic acid. The ratio of palladium acetate and the co-catalyst is determined according to the application field and performance of the polyketone resin product. In addition to the HF-PK1 product brand, the present invention can also produce five brands of polyketone resin products. Each batch of catalyst system ratio determines each brand. The specific catalyst formula is as follows:

[0052] Catalyst formula ratio table

[0053] Product Brand HF-PK1 HF-PK2 HF-PK3 HF-PK4 HF-PK5 PC ingredient ratio 1 1 1 1 1 DHP ingredient ratio 3.00 2.67 2.33 2.00 1.50 MA ingredient ratio 21.00 18.00 12.00 6.00 3.00 NMP ingredient ratio 10000 10000 10000 10000 10000

[0054] Catalyst addition table

[0055] Product Brand HF-PK1 HF-PK2 HF-PK3 HF-PK4 HF-PK5 PC dosage kg 0.15 0.15 0.15 0.15 0.15 DHP dosage kg 0.45 0.4 0.35 0.3 0.225 MA batching quantity kg 3.15 2.7 1.8 0.9 0.45 NMP dosage kg 1500 1500 1500 1500 1500 total 1503.75 1503.25 1502.3 1501.35 1500.825

[0056] PK (HF-PK1) was prepared by conventional process using the prepared catalyst, wherein the carbon monoxide flow rate at the material inlet was 3.230 t / h, the ethylene flow rate was 2.900 t / h, the propylene flow rate was 0.500 t / h, the added catalyst flow rate was 0.000469 t / h, the carbon monoxide flow rate at the polymerization kettle outlet was 0.048 t / h, the ethylene flow rate was 0.044 t / h, the propylene flow rate was 0.008 h / h, the polymer flow rate was 6.530 t / h, the catalyst flow rate was 0.000469 t / h, and the catalytic efficiency of the converted catalyst was 6.530 / 6.630*100%=98.49%.

[0057] Comparison of catalytic performance of Example 2 with conventional catalysts

[0058] Main physical properties of conventional catalyst system

[0059]

[0060] The main physical properties of the catalyst system of the present invention are shown in Table 1.

[0061]

[0062] Comparison of catalytic performance with conventional catalysts

[0063]

[0064]

Claims

1. A production system for a PK catalyst, characterized in that: It comprises a palladium acetate feeding tank (1), a ligand feeding tank (2), an organic acid feeding tank (3), and a catalyst reaction kettle (4). The palladium acetate feeding tank (1), the ligand feeding tank (2), the organic acid feeding tank (3) and the catalyst reaction kettle (4) are all provided with a heat exchange interlayer and a stirring device. The feed port of the palladium acetate feed tank (1) is connected to a palladium acetate source and an N-methylpyrrolidone source, the feed port of the ligand feed tank (2) is connected to a 4,6-dihydroxy-2-methylpyrimidine source and an N-methylpyrrolidone source, and the feed port of the organic acid feed tank (3) is connected to a maleic acid source and an N-methylpyrrolidone source. The palladium acetate feeding tank (1), the ligand feeding tank (2), and the organic acid feeding tank (3) respectively feed materials to the catalyst reaction kettle (4).

2. The production system of PK catalyst according to claim 1, characterized in that: The palladium acetate feeding tank (1), the ligand feeding tank (2), the organic acid feeding tank (3) and the catalyst reaction kettle (4) are all filled with inert gas.

3. The production system of PK catalyst according to claim 1, characterized in that: It also comprises a catalyst intermediate tank (5), through which the catalyst reactor (4) provides PK catalyst to the polymerization process, and the catalyst intermediate tank (5) is filled with inert gas.

4. A process for synthesizing a PK catalyst using any production system of claims 1 to 3, characterized in that: The following steps are involved: 1) Pass 80-90°C hot water into the heating interlayer of the palladium acetate feeding tank, the ligand feeding tank, the organic acid feeding tank, and the catalyst reactor and keep it warm; 2) respectively adding N-methylpyrrolidone into the palladium acetate feeding tank, the ligand feeding tank, and the organic acid feeding tank, and stirring; 3) Add palladium acetate to the palladium acetate feeding tank, control the mass ratio of palladium acetate to N-methylpyrrolidone to 1:4000, until it is completely dissolved; add 4,6-dihydroxy-2-methylpyrimidine to the ligand feeding tank, control the mass ratio of 4,6-dihydroxy-2-methylpyrimidine to N-methylpyrrolidone to 1:888.9, until it is completely dissolved; add maleic acid to the organic acid feeding tank, control the mass ratio of maleic acid to N-methylpyrrolidone to 1:158.7, until it is completely dissolved; 4) Control the palladium acetate feeding tank and the ligand feeding tank to feed the catalyst reactor at the same time, and stir the reaction at normal pressure for 3 hours; 5) Control the organic acid feeding tank to feed the catalyst reactor, stir and react for 2 hours under normal pressure to obtain a mixture containing PK catalyst.

5. The process according to claim 4, characterized in that Step 2) The mass ratio of N-methylpyrrolidone in the palladium acetate feed tank, the ligand feed tank, and the organic acid feed tank is 6:4:

5.

6. The process according to claim 4, characterized in that In step 3), palladium acetate is solid particles, 4,6-dihydroxy-2-methylpyrimidine is solid particles, maleic acid is solid particles, the molar ratio of palladium acetate to 4,6-dihydroxy-2-methylpyrimidine is 1:1.5-3, and the molar ratio of palladium acetate to maleic acid is 1:3-21.

7. The process according to claim 4, characterized in that Step 5) The mixture containing the PK catalyst is sent to a PK polymerization process, and the solvent used in the PK polymerization process is N-methylpyrrolidone.

8. A PK catalyst, characterized in that The method is prepared by any one of claims 4 to 7.

9. Use of the PK catalyst according to claim 8 in catalyzing a PK polymerization process.

10. The use according to claim 9, wherein the PK polymerization process uses ethylene, carbon monoxide and propylene as polymerization monomers, and the mass ratio of the added amount of PK catalyst to propylene is 4.69:500.

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